The present invention concerns an apparatus and method for isolating parts or other objects for later use. More particularly, the present invention is for an apparatus and method for creating a stream of parts or other objects at a point where they may be gathered and isolated.
As part of many manufacturing processes, it is necessary to isolate a single part from a container containing a large supply of those parts for use in the manufacturing process. The prior art discloses vibrating mechanisms that are employed to arrange the parts into an array from which a gathering device captures and removes a part for use in the manufacturing process. The most common of these vibrating mechanisms is a bowl feeder which consists of a bowl shaped container filled with parts to be used in the manufacturing process. The bowl feeder includes a spiral track that runs from the bottom of the container to the top of the container around an inner surface of the bowl. When the bowl is vibrated the parts move up the spiral track and are delivered to the top of the bowl, possibly in a particular orientation.
Vibrating mechanisms have difficulty handling small parts. Small parts have a tendency to bounce excessively with the vibration of the bowl and are prone to bounce out of the container, fall off the vibrating track, and have a tendency to jam the machine.
In order to eliminate these difficulties, the prior art discloses isolating the parts by pouring large quantities of parts in a continuous cascade over the gathering device which captures and removes the required parts. This approach avoids the problems created by vibrating feeders but it requires a large quantity of parts and a mechanism for recycling non-captured parts back into the cascade. Effectively, such a system requires a relatively large amount of parts to xe2x80x9cprimexe2x80x9d the system to create a continuous cascade. The longer the cycle time of the parts through the feeder system, the more parts are necessary to xe2x80x9cprimexe2x80x9d the system.
In addition, since the parts fall into the gathering device in a random fashion, there is a relatively low probability that a particular part will be gathered. Instead, this method relies upon a large volume of parts cascading over the gathering device to ensure that the required number of parts are captured and removed, increasing the number of parts necessary to operate the system.
In applications where the parts involved are relatively expensive, the cascade system requires a large capital investment in parts needed to create a continuous cascade to be captured relative to the number of parts are actually captured. Where the parts are expensive, the cascade method can be burdensome or even cost prohibitive for some manufacturing process.
The present invention relates to an apparatus and method for creating a cascade of parts at a specified location where they are captured, isolated and removed by a gathering device while greatly shortening the time necessary to recycle parts.
A part feeder comprising constructed in accordance with the invention includes a generally cylindrically shaped feeder having a feeder housing defining a cavity bounded by an inner surface having one or more spiral grooves extending from a front end to a back end of the inner surface of the feeder housing. A generally cone shaped end cap is dimensioned such that a cone base engages the back end of said cylindrically shaped feeder housing. The end cap has an inner surface which faces the cavity which defines one or more parts delivery grooves that extend into the inner surface which extend radially from a cone top to the cone base. A drive rotates the cylindrically shaped feeder about an axis of rotation to move parts along the plurality of spiral grooves to the one or more parts delivery grooves for delivery to a discharge zone at the end of said one or more parts delivery grooves.
A presently preferred embodiment of the invention includes a parts feeder having a generally cylindrically shaped parts feeder housing defining a cavity which is bounded by an inner surface having a plurality of spiral grooves. The grooves are spaced apart from each other and extend from a front end to a back end of the inner surface of the feeder housing. A cone shaped end cap which is dimensioned to engage the back end of said cylindrically shaped feeder housing has an inner surface and an outer surface with the inner surface forming a plurality of grooves cut into the inner surface of the cone. The grooves extend from a top of the cone to its base and are spaced about a periphery of the cone to align with corresponding spiral grooves in the feeder housing. A drive mechanism rotates both the cylindrically shaped feeder and the cone about an axis of rotation. This moves parts along the spiral grooves to the radial grooves in the cone for delivery to a discharge zone at the top of the cone.
The present invention also includes a method of isolating parts by inserting the parts to be isolated into the inner cavity of a cylindrically shaped feeder having spiral grooves which extend along an inner surface of the feeder. After the parts to be isolated are placed in the feeder, the feeder is rotated forcing the parts to move along the spiral grooves to the back of the feeder where they are moved into grooves aligning radially from the base to the top of the cone. As the cylindrical feeder continues to rotate, the parts, which are trapped in the grooves in the cone, rotate with the cone until they reach a position where they slide down the grove in which they are captured and fall through a discharge zone at the end of the cone. An interceptor may then be inserted into the stream of parts falling through the discharge zone and capture and remove some of the parts.
In addition, the present invention facilitates removal of the parts from the apparatus. By reversing the direction of the rotation of the cylindrically shaped feeder housing, the direction that the parts move in the feeder can also be reversed. The parts are forced by the spiral groves to the front of the feeder and out an open portion of the feeder housing. This process greatly facilitates unloading the parts and shortens the part change over time.
The present invention significantly shortens the time necessary to recycle the non-captured parts back into the cascade. The present invention, therefore, reduces the number of parts necessary to xe2x80x9cprimexe2x80x9d the system and the capital costs associated with those extra parts. In addition, the present invention facilitates removal of the parts from the apparatus reducing the time required to change the type of part being captured, isolated and removed.
These and other objects, advantages and features of the invention will become better understood from the accompanying detailed description of a preferred embodiment of the invention which is described in conjunction with the drawings.